Dictionary Q

See "quality factor".

References:

QFD

See "quality function deployment".

References:

QML

See "qualified manufacturers list".

References:

QMP

See "quality management plan".

References:

Q(n)(x)

See "data output".

References:

QSY

See "transfer acknowledge output".

References:

quad flatpack

A surface-mount package whose terminals are on four sides and consist of metal pad surfaces (on leadless versions) or leads emerging from the package.

NOTE 1 The package leads may be formed to facilitate surface mounting.

NOTE 2 The small-outline package is similar except for having terminals on only one or two opposite sides of the package.

References:

JESD21-C#, 1/97
JESD30D, 7/06

quad word

A character string or binary element string that, in a given system, has four times the length of a word.

References:

JESD100-B, 12/99

qua1ification

The process of demonstrating that an entity is capable of meeting or exceeding the specified requirements.

References:

EIA-599-A#, 6/98
JEP143, 5/04
JEP148, 4/04

qualification family

(1) Products sharing the same technology and process.

(2) Products sharing the same process technology.

References:

JESD74, 4/00

JESD74A, 2/07

qualification requirements

The quality and reliability properties of the product that demonstrate compliance with the application requirements.

References:

JEP148, 4/04

qualified manufacturers list (QML)

A list of manufacturers whose production lines have been certified and qualified by the Defense Supply Center Columbus (DSCC) for the production of devices used in military or space applications.

References:

JEP133B, 3/05

qualifying activity

(1) The organizational element that grants certification status; this element may be a part of a) the acquiring activity; b) a quality organization within the manufacturer's company that is independent of the group(s) responsible for the device production, screening, and marketing; or c) an independent third-party organization.

(2) The organizational element of the government that grants certification and QML status.

References:

JEP133B, 3/05

quality

Conformance of a product to requirements, or perceived fitness for its intended use(s).

References:

JESD46C, 10/06

quality characteristic

A process or device attribute that may affect the final product quality or reliability.

References:

JEP121A, 10/06

quality factor (Q)

Two pi (2π) times the ratio of the maximum energy stored per cycle to the energy dissipated per cycle at a given frequency.

NOTE The Q of an inductor at a frequency is the magnitude of the ratio of its reactance to its effective series resistance at that frequency. (IEEE Std 100.)

References:

JESD10, 9/81

quality function deployment (QFD)

(1) A technique for analysis of the interrelationships between different requirements.

(2) A structured method in which customer requirements are translated into appropriate technical requirements for each stage of product development and production.

References:

EIA-557-A, 7/95

JEP132#, 7/98

quality management plan (QMP)

A plan described in military specifications (MIL‑PRF‑19500, MIL‑PRF‑38534, and MIL‑PRF‑38535) that describes the methods a supplier uses to assure conformance to the applicable requirements, including design, manufacturing, and verification.

References:

JEP133B, 3/05

quality rating

An assessment of the metrics established to evaluate the quality.

References:

JEP146#, 6/03

quantity symbol

A letter symbol that is used to represent a physical quantity or a relationship between quantities.

NOTE The letter symbol used to designate a quantity or parameter shall be a single letter. This single letter, referred to as the primary symbol, may be modified by subscripts or superscripts.

References:

JESD77-B, 2/00
JESD99B, 5/07

quantization error, inherent (of an ideal analog-to-digital converter)

Within a step, the maximum (positive or negative) possible deviation of the actual analog input value from the nominal midstep value.

NOTE 1 This error follows necessarily from the quantization procedure. For a linear analog-to-digital converter, its value equals ±½ LSB.

NOTE 2 Use of the term "resolution error" in place of "inherent quantization error" is deprecated, because "resolution" as a design parameter has a nominal value only.

References:

JESD99B, 5/07

quantum efficiency (of a photosensitive device)

The ratio of the number of effective electron-hole pairs produced within the device to the number of incident photons.

NOTE For devices that internally amplify or multiply the electron‑hole pairs (such as phototransistors or avalanche photodiodes), the effect of the gain is to be excluded from quantum efficiency.

References:

JESD77-B, 2/00

quantum efficiency, external (of a photoemitter)

The ratio of the number of photons radiated to the number of electrons flowing into the radiation source.

References:

JESD77-B, 2/00

quantum efficiency, internal (of a photoemitter)

The ratio of the number of photons internally produced to the number of electrons flowing into the radiation source.

References:

JESD77-B, 2/00

quiescent current

The dc current through a terminal when no signal is applied.

References:

JESD99A.01, 5/0

quiescent output voltages (V_O)

The dc voltage at an output terminal with reference to a common terminal, normally ground, when no signal is applied to the input.

References:

JESD99B, 5/07

quiescent voltage

The dc voltage at a terminal when no signal is applied.

References:

JESD99B, 5/07

quoted failure rate (λq)

The predicted failure rate for typical operating conditions.

NOTE The quoted failure rate is calculated from the observed failure rate under accelerated stress conditions multiplied by an acceleration factor; e.g., λ_q = λ_o ∙ A_T, where λ_q is the quoted (predicted) system failure rate at some system temperature T_s, λ_o is the observed failure rate at some test temperature T_t, and A_T is the temperature acceleration factor from T_t to T_s. When multiple failure mechanisms and thus multiple acceleration factors are involved, then a proper summation technique, e.g., sum-of-the-failure-rates method, is required.

References:

JEP122E, 3/09
JEP143B.01, 6/08

Dictionary Q

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